Millions of people from Bristol to London might have to be evacuated if a Chernobyl-style explosion occurred at Oldbury nuclear reactor. Anti-nuclear campaigners have released a map based on the radiation hotspots map for Chernobyl which was produced for the United States' Central Intelligence Agency.

The Chernobyl disaster occurred after misguided experimentation with the reactor. British nuclear experts say British reactors are of better design and that the actions which led to the Chernobyl disaster would never happen in Britain.

Each nuclear power station in Britain has a detailed emergency planning zone around it within which arrangements are made for public protection. The boundary is defined in relation to the maximum size of accident which can reasonably be forseen. For Oldbury that is 1km.

Jim Duffy, a spokesman for the Stop Hinkley and Shut Oldbury campaign, said "Most people think that they live far enough from a nuclear reactor not to have to worry. But as we approach the 20th anniversary of Chernobyl, this map shows that such an accident could require long-term evacuation of parts of London and a swathe of the Home Counties as well as Bristol and the surrounding area." But Tim Jones, spokesman for British Nuclear Group, which manages Oldbury, said: "It is very easy for someone to draw lines on a map, but you have to look at the science behind these claims."